In your demo for the new Sites feature, I followed along, took the script, put it into the head of my home page, and as expected, when viewing from a PC, it stays on the PC based site. When viewed from a smartphone, it goes to the mobile site.  However, I can't ever get BACK to the pc based site because the script is there telling it to always go to the mobile site.

I know it seems to be a real simple question, but how do I prevent this loop effect?

Create a dummy page that will redirect around the script?  Any recommendations?